Earthenware body



' and the method "them.

o 1011153 mmte' give the new? m ar Dec.- 11, 1934 1,924.1" as uiarnsnwmaont Sprout, Ohio, to

PATENT YOFFICE Incorporated, New

,N 1., a corporation of New York I Nomraw lng. Continuation of application Serial 1N0; 560.811; September}, 1931. This applies.- um august 2.4, weasel-mm. 30,247

' .mv enfleu to the manufacture oi It. both the -new 55' new -product'sy-oi thisinvention are which are de.--rv

sirableinwalltlle. tab s mJwg I useior qbtained mm the inines'ot Hemp; It contains con-' indelible a'flux' of therefore particu- !orthe manufacture of these earth.-

bodies' :01 thisinvention may made-'i'mm pyrophyllitehaving an al-v about 24%.: the melting mfi lthe alkali content.is..'to be preferred.

eel- .8 aluminagcontentslma'y vary from about 60 to 70% and from about-21 to 80%- re eomb nd..-flu.xi entent. that is. Naiofand mo 1 smar s 5%. The.

. Eh .=9 n

W m' e 915 18 sericite "thick a glazed coating; Y The colorot the finished were 01 1e reams-1o) I I y oi this invention in the condition in p whichit is removed from the mine. After grindit may be' advantageously air-floated to separateit from coarse particles-oi silica and iron, etct Further iron may be separated by a mag.-

netic .separator i! desirable. The presence .0!

magnesium compounds is an-advantagesince increases the thermal shock of the vitrified prodnets and thus reduces the time requiredi'or flring and cooling. A small percentage of is alsodesirable to supplement the reduction in the vitrification point due to the presence. or al- .kalis. The presence of any considerable quantity oi. compounds which increase the. ratio oi to silica appreciably is not desirable. v

The improved semi-vitreous earthenware bodies made from a mixture oi! such crude pyrophyllite and kaolin, etc. have many desirable properties. Their absorption will ordinarily be low, but will depend upon the method of manufacture. Wall 20 tile for example which is ordinarily prepared by a dry pressing process will usually have an absorption of about'14% although it maybe aslow as 5% or as high as 16%. General ware bodies such as plates, pitchers, etc. made-by plastic molding or casting usually have an absorption of about 8%, although-it may be as. low as 6% or ashigh as The absorption and shrinkage of the semi-porcelain bodies of-this invention are more uniform 9 over a wide range of temperaturesthan the absorption and shrinkage of ordinary semi-porcelain ware. The capacity of continuous kilns Iorflring 'bodies-ot this invention is therefore greater than i n the capacity of the same kilns tor other bodies. A larger quantity of ware can be-fired in a continuous kiln without any material increase in fuel cost since the ware'cloes not have to 'remamim the hot 'zone of the kill: as long as other"'ware,, in order to be properly matured. Further, due-'to"- the'more uniform absorption ofthe 'semip'orce- I lai'n' bodies of this invention theydonot require the same careful supervision [and even treatment j during glazing required by other-productsand 'the'glazed coating will be more uniform inthicb' .ness. This materially decreases "crazingl and other defects which res ult from; the usev oi too ven ion a is more uniformthanthe color oih-Nvai'e whieli 9 does not contain apyrophyllitetz; The :unevensdiscoloration of ordinary earthenware during::iiring- -i imake's the-production'oi stainedbodiesegrpensive. '1'hey are now generally manufactured-{roommate {placedmlcerm sections at where. the heat treatment is most uniform, or

lure of substantially the same shadeis obtained by selection after firing. The use of pyrophyllite in bodies which are to be fore particularly advantageous.

It has been found that by using crude pyrophyllite of the type here contemplated in the manufacture of semi-porcelain bodies a large peroentage'of the cheaper kaolins such as Georgia or South Carolina kaolin can be employed to replace the more expensive kaolins such-as English china clay or North Carolina 'kanlin without the undesirable effects which result from them of such,

large percentages of cheap kaolin in ordinary m-P rcelain; Generally the use of. more than 7 to 10% of such cheap kaolin produces'flrecracking and other und sirable eilects, but. by using a' considerable percentage of this crude nyrophyllite, it has been found that as much as 20% of 'theeheaper Georgia and South Carolina. kaolin can be employed and that a superior-product lspl'oduced. I

It has that raw uncalcined oflthewaterdoesnothavethesameshortening eilect it is therefore desirable to vcalcine the wrophyllitemed in the manufacture of were wmchiseastmmomedmaplasuc PM wan, tile, for-example. it

50% of pyrophyllite give satisfactory bodies havin: a long vitrification range. 'They have rel-- and shrinkage over name of thing There is than amongthe usual and -f,-eld-' mar satisf "o i (got per mermarinmine of the satisfactory stained is there- 7 good color as the ball clays of The following formula have been v from a mixture mmo.

g; Semi-vitreom' i thete'nt compolm h the foll wing formula has found to give results; were spar and flint has for certain purposes to were which does not contain both of these lnzredients.

In the manufactiue of I I I W I to substitute bondelays from sippi and Illinois for a portion in the-mix. These bond clays do ,not have as Tennessee but with the use white body may be obtained by using tively small amounts of these bond clays whichadd to the strength of the body:

The n amount-of water be added I a plastic condition should contain water and material that is to-be terial'thatis'tobecastmayalsoadvan litei 1 apnlication'is a or 2': aura having in thehydrated Ichim' ox'ui 1 s.

dedintheusuaiwayaccord in g'to which'oontains feld-Iv been found, to be superior For example,'material that F to.

general to the present. invention it is ary an Missisof-the ball clay Kehtllcw Ind of crude. pyrophyllite or the one ontemplated herein a satisfactory ntainabout 30% of water. Ma-' a small amount of maamaem mmmar "mi 1mm 1,os4,1es

from a mixture comprising clay and from 35% to 50% ot pyrophyliite.

'l. Semi-vitreous earthenware bodies made from a mixture comprising clay and at least 10% of pyrophyllite containing sericite naturally associated therewith.

B. Semi-vitreous earthenware bodies made from a mixture comprising clay and at least 10% of pyrophyllite containing alkali and alkaline-earth compoundsnaturally associated therewith.

9. Semi-vitreous earthenware bodies made from a mixture comprising clay and at least 10%, of pyrophyllite containing alkali, and alkaline-earth oxidesnaturally associated therewith.

10.'Semi-vitreous earthenware bodies made from a mixture comprising clay, at least 10% 0t p yr phyllite, kaolin, ball clay, feldspar, and flint associated therewith,

proximately 1%% to 4% potassium oxide, and

less than 1% each of magnesium oxide and sodium oxide.

IRA ELMER SPROAT.

Certificate of combs Patent N6. 1,984,163.

1 IRA ELMER SPROAT December 11, 1934.

It is hereby certified that error appears in the printed specification of the above numbered patent req Al,O .4Si,O.H,O read correction as follows: Page 2.,sec0nd column, line 55, for l,O,.4StO,.H,O; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Ofiice.

Signed and sealed this 2nd day of January, A. D. 1935.

. LESLIE FRAZER, Admg Commissioner of Patents.

1,os4,1es

from a mixture comprising clay and from 35% to 50% ot pyrophyliite.

'l. Semi-vitreous earthenware bodies made from a mixture comprising clay and at least 10% of pyrophyllite containing sericite naturally associated therewith.

B. Semi-vitreous earthenware bodies made from a mixture comprising clay and at least 10% of pyrophyllite containing alkali and alkaline-earth compoundsnaturally associated therewith.

9. Semi-vitreous earthenware bodies made from a mixture comprising clay and at least 10%, of pyrophyllite containing alkali, and alkaline-earth oxidesnaturally associated therewith.

10.'Semi-vitreous earthenware bodies made from a mixture comprising clay, at least 10% 0t p yr phyllite, kaolin, ball clay, feldspar, and flint associated therewith,

proximately 1%% to 4% potassium oxide, and

less than 1% each of magnesium oxide and sodium oxide.

IRA ELMER SPROAT.

Certificate of combs Patent N6. 1,984,163.

1 IRA ELMER SPROAT December 11, 1934.

It is hereby certified that error appears in the printed specification of the above numbered patent req Al,O .4Si,O.H,O read correction as follows: Page 2.,sec0nd column, line 55, for l,O,.4StO,.H,O; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Ofiice.

Signed and sealed this 2nd day of January, A. D. 1935.

. LESLIE FRAZER, Admg Commissioner of Patents. 

